Mordant Calculator

Mordant weight from fiber weight and type (alum, iron, tannin).

Fiber weight (g)

Mordant (% OWF)

Assistant mordant (% OWF)

Liquor ratio (X:1)

Number of mordant baths

Tab to move between fields

Mordant per bath (g)

Assistant per bath (g)30

Bath volume (L)10

Total water (L)10

Mordant concentration (g/L)7.5

Total mordant all baths (g)75

How to Use This Calculator

How the result changes with Fiber weight (g)

Fiber weight (g): Dry weight of fiber or fabric to mordant, in grams.
Mordant (% OWF): Mordant dosage as % on weight of fiber. Alum: 12-20%, iron: 2-4%, tannin: 8-12%.
Assistant mordant (% OWF): Cream of tartar or other assistant. Use 6% with alum on protein fibers; 0 if not needed.
Liquor ratio (X:1): Water-to-fiber ratio. 20:1 typical for mordanting in a pot.
Number of mordant baths: Some fibers benefit from multiple mordant baths (e.g., cellulose with tannin + alum).

Mordant per bath (g): Grams of mordant needed per bath.
Assistant per bath (g): Grams of assistant mordant (cream of tartar) per bath.
Bath volume (L): Water volume per mordant bath.
Total water (L): Total water across all mordant baths.
Mordant concentration (g/L): Mordant concentration in the bath.
Total mordant all baths (g): Total mordant if re-dosing for each bath.

Identify Input Parameters
4 parameters
Fiber weight (g) = 500, Mordant (% OWF) = 15, Assistant mordant (% OWF) = 6, Liquor ratio (X:1) = 20 = 5 input(s) provided
Calculate Mordant per bath
Mordant per bath = fiberWeightG * (mordantPctOwf / 100)
75 = 75
Calculate Assistant per bath
Assistant per bath = fiberWeightG * (assistantPctOwf / 100)
30 = 30
Calculate Bath volume
Bath volume = (fiberWeightG / 1000) * liquorRatio
10 = 10